Background: Cardiovascular diseases (CVD) including hypertension, are characterized by underlying systemic inflammation. Periodontitis, which can impact the systemic inflammatory burden has recently been linked to high blood pressure (BP). However, the relationship of gingival bleeding, as an easily accessible marker of periodontal disorder, with hypertension, remains unclear.
Methods: Survey-based propensity score matching (PSM) incorporating major confounders shared between hypertension and periodontal diseases was applied to cross-sectional NHANES III data from 5396 adults at least 30 years old who underwent BP measurement and periodontal examination, identifying two matched groups with and without gingival bleeding. The association of bleeding gums with SBP (mmHg) and high/uncontrolled BP was then assessed with generalized additive models incorporating inflammatory markers. Stratification by periodontal status (healthy; gingivitis; stable periodontitis; unstable periodontitis) was performed. Variables importance was estimated using machine learning.
Results: Gingival bleeding (gingivitis; unstable periodontitis) was independently associated with +2.6 mmHg (P < 0.001) SBP compared with no bleeding (healthy periodontium; stable periodontitis), and with greater odds (OR = 1.42; 95% CI = 1.19-1.68; P < 0.001) of high/uncontrolled BP. Participants with unstable periodontitis had higher SBP than those with stable periodontitis (+2.1 mmHg; P < 0.001) or gingivitis (+5.3 mmHg; P < 0.001). Unstable periodontitis and gingivitis were consistently associated with increased risk of high/uncontrolled BP (OR = 1.65, 95% CI = 2.14-1.82; OR = 1.49, 95% CI = 1.22-1.82, respectively). Inflammatory markers allowed a maximum of 12% gain in the models' predictive power.
Conclusion: Gingival bleeding contributes to shaping the relationship between periodontal diseases and BP, but the burden represented by periodontitis is also crucial. Periodontal evaluation might be of importance in difficult to control hypertension.